Did you update to a newer rollup on CRM 2011 since this started happening? There was an issue about a year ago that caused problems and errors when attempting to modify views. Once you made changes to a view and saved it, you would receive an
error when attempting to make further changes. It was a major problem if you made changes to out of the box views. The work around was to copy an existing view and modify it instead of modifying out of the box views until the fix was released.
I don't remember what rollup specifically caused this but it was happening in CRM online as well when CRM online was still on CRM 2011. But it was sometime early last year.
I haven't seen the issue with the recent rollups. So if you are not current, and find that the last rollup installed caused this, you may want to look at installing a newer rollup.
Jason Peterson
